Vertical transistors are suitable as transistors which withstand high voltage, compared to lateral transistors, and are therefore applied to power elements used in the field of power electronics, for example.
Examples of the vertical transistors include metal-insulator-semiconductor field-effect transistors (MISFETs) or insulated gate bipolar transistors (IGBT).
Patent Document 1 discloses a silicon carbide semiconductor device including a surface channel layer placed on a surface of a base region such that a source region and a silicon carbide epitaxial layer are connected to each other in order to increase the channel mobility.